


The Masks We Hide Behind

by ANekoForMe



Series: Faulty Reasoning [1]
Category: Ao no Exorcist | Blue Exorcist
Genre: Basically all the characters are in this, Completed, Fluff and Angst, M/M, OOC characters, Somewhat mature Amaimon
Language: English
Status: Completed
Published: 2015-09-27
Updated: 2016-01-09
Packaged: 2018-04-23 15:25:32
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 11
Words: 8,780
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4881946
Author URL: https://archiveofourown.org/users/ANekoForMe/pseuds/ANekoForMe
Summary: <blockquote class="userstuff">
              <p>Rin has always been sick. He has always kept it hidden, never wanting his friends and brother to worry. As the symptoms get worse, only one person notices.</p>
            </blockquote>





	1. Chapter 1

When Rin was nine years old, he was diagnosed with anemia. He had been having nosebleeds often, and Shiro had decided to take him to the doctor. The doctor, having heard Rin got into fights often, asked about the injuries he received from said fights. Shiro told the doctor that he bruised easily, and that when Rin got cuts from the fights (or anything else mind you) they often bled a lot, no matter the size. Topped with the nosebleeds he quickly concluded that the boy had a minor case of anemia and prescribed iron supplements. Shiro had thanked the doctor and left, hoping his son would get better.  
Rin never did. He actually got worse throughout the years, but he never told anyone, not wanting to be a bother. For the next few years, he took the supplements as he was told to. He never told Shiro they did nothing, and made sure no one else, especially Yukio would find out.  
The symptoms were getting worse. The nosebleeds happened often, and his gums would almost always bleed. He was constantly fatigued and often irritated, but he never told anyone about the new symptoms.  
Then, it happened. Shiro was killed by Satan because of Rin. He joined the Cram School to train to beat Satan. He actually made friends with the other students and had started rebuilding the broken bond he had with his brother, he was so happy. But, his condition became harder to hide. Then, the events with Amaimon happened, and everyone found out he was the son of Satan. He began training his powers with Shura and the Gehenna Gate incident happened. No one seemed to notice that he had bled far more than he should have. After he and Yukio defeated Satan, everyone went back to normal. Not wanting to focus on what happened.  
In their haste to do this, no one noticed how much worse Rin was doing. The bloody noses and bleeding gums, topped with an almost constant fatigue were so much worse. He was able to hide the bleeding and bruising, and whenever someone saw how tired he was, they would brush it off as typical Rin. But, he was actually doing so poorly that he decided it was best he see a doctor.  
The doctor, when having heard his patient had anemia with symptoms that had worsened since when he was first diagnosed, immediately ordered a bone marrow biopsy. When they go the results, what he found was shocking.  
The results showed that Rin Okumura did not just have anemia, he had the most severe case of chronic idiopathic aplastic anemia that the doctor had ever seen. When they called Rin back to the clinic to see the results, he didn't seem to see how this was much different than what he was diagnosed with. They were both anemia? What was the difference?  
"I'm not sure I understand doctor. How is this different from what I was first diagnosed with?" Rin asked.  
"You were first diagnosed with regular anemia, an iron deficiency. Idiopathic aplastic anemia is when you're bone marrow stops making new blood cells. It's cause is unknown. I'm so sorry to say this, son, but you have a chronic condition of it. If it was acute, it would be much easier to treat, but with how long it's been left untreated there's not much we can do." The doctor told Rin. "We can still offer you the treatments though. Untreated chronic aplastic anemia is almost impossible to cure, but we could try.  
Rin spoke after some time. "No thanks doctor. I think I'll forgo all treatment."  
"Why?!" The doctor frantically asked.  
"I already know I'm not going to make it. I'd rather not give my friends false hope to only crush it in the end. Thank you very much doctor. Goodbye." And with that, Rin left.  
The next day, Rin acted completely normal. Not at all like he had just got the news that he was dying. He didn't want to leave the people he had come to care about with sad memories of him.  
Yukio got a long mission after class, so Rin was left in the dorm all alone. He quickly gave up on homework, the fatigue impossible to work through. It was at this point that he finally broke down. Rin sobbed himself to sleep that night.  
When he woke up that morning, he was quite thankful it was the weekend. He had slept quite late and was feeling worse than ever from how he had fallen asleep. Then, the coughing began.  
Being a demon, Rin had never had a cold before. But, he remembered his condition caused him to be more susceptible to infections. Shit! He probably had a cold now.  
Then he felt something coat his hand. He looked at it and saw blood. Most likely a mixture from coughing and his now bleeding gums. The familiar dripping from his nose had begun as well.  
As he continued coughing, he heard something he didn't expect to hear. Someone was opening the window.  
"Rin, I want to play!" Amaimon somewhat whined.  
It was then he saw the other demon in the fetal position coughing up blood. It was all over his hands and clothes, dripping from both his nose and mouth.  
When Rin realized that it was Amaimon. He feebly tried to grab his sword. But what Amaimon said next made him freeze.  
"Why didn't you tell anyone you were this sick?"  
"What makes you think I'm sick? I could have just been beaten up before you came? Besides, why would you care if I was sick?" Rin used most of his fading strength to reply, and collapsed back onto the floor. Amaimon quickly ran over to him.  
"You honestly thought someone wouldn't notice how different you've been acting? It was easy to figure out something was wrong. Besides, why wouldn't I care?" Amaimon spoke all of this softly in Rin's ear.


	2. Chapter 2

The words shocked Rin. He had never thought he'd hear those words from the demon who had tried to kill him many times. What the hell were they even supposed to mean?  
While Rin was pondering this, he stopped coughing. Blood was still leaking from his nose and gums though.   
He decided to be brave and ask Amaimon what he meant. "What the hell do you mean by that?"  
Amaimon looked at Rin confused. Then it clicked. Rin didn't know anything about how demons are raised. This had Amaimon seething in anger.   
"For more powerful demons, fighting others is a great way to discard our boredom. The fact that you keep living and almost defeated me intrigued me greatly. After watching you for a while, my interest grew like any demon's would. After the gate incident my interest became possessive. You've always had a strange smell, a sickly one. I ignored it whenever we fought, not really thinking anything of it. It became so much stronger after the incident. I began to worry about what it was and realized I cared. You should be happy, it is very rare for a demon to care about another. I followed you when you went to the doctor again and had my suspicions confirmed; you were sick and from your body language it wasn't good. Would you mind telling me what you have?" After he finished this, Amaimon pulled out a sucker and unwrapped it before putting it in his mouth.   
Rin sat there in stunned silence. Never would he have thought he would hear the demon say this. Maybe it was the blood he was loosing right now, but he believed what the demon was saying was true. Rin dropped any remaining hostility he had after Amaimon spoke.   
"I have idiopathic aplastic anemia." Rin said.   
"What's that?" Amaimon asked.   
"Somethings wrong with my bone marrow and the doctors don't know what. And because of this problem, not enough blood cells are being produced along with my platelets."  
Rin was still bleeding and it was getting damn annoying. He tried standing to get to the clotting medicine he kept for times like this. It didn't cure his disease, but it helped treat and hide his symptoms. As soon as he took the first shaking step to get the medicine, he collapsed.   
"Damn anemia, leaving me so weak," Rin grumbled.   
Amaimon rushed over to Rin. "What are you trying to do?" Concern evident in his voice as he asked Rin.   
"Could you get me my medicine?" Rin blushed heavily, or as much as you could while having a constant stream on blood coming out of your nose and gums.   
"Where's it at?"  
"The desk drawer over there."  
Amaimon quickly padded over to the drawer and pulled out the medicine. He walked back and handed it over to Rin.   
"What's it do?" Amaimon asked.   
"It helps my blood clot. It'll stop my nose and gums from bleeding for a little bit."  
Rin quickly took the medicine. A few minutes later the bleeding had stopped.   
"I should probably get cleaned up." This was really embarrassing for Rin, but he knew he wouldn't be able to do this alone so he asked. "Could you possibly, um, help me?" Rin's voice getting quieter as he talks more.   
Amaimon didn't seem fazed by the question. "Sure."  
He then proceeded to bend down and pick up Rin bridal style. Rin was to weak to say anything about it. He was quickly taken to the bathroom where Amaimon undressed him and helped wash the blood off Rin.   
Amaimon wrapped Rin in a towel, which he had learned humans used to dry themselves and cover up after getting wet. He picked Rin up again and was about to head back to Rin's room when he heard something. Rin heard it too, even in his weakened state.   
The door to the dorms had slammed open and Rin's exorcist friends could be heard laughing and calling out for Rin.   
Both Amaimon and Rin had the same thought, 'Oh shit!'

**Notes for the Chapter:**

> Sorry it took so long to get this up. My teachers had decided they wanted to assign ridiculous amounts of homework on their poor unsuspecting students. Hope the chapter was okay. Oh, I forgot to mention that this is about two years after the Gehena Gate incident. Rin's about 17 or 18 in this fic.


	3. Chapter 3

**Notes for the Chapter:**

> So sorry for being late!! I got sick and, like I mentioned before, my teachers have been giving out lots of homework.  
> This one is a lot shorter than my normally short writing, but I thought you guys deserved an update. Well, enjoy the next chapter.

"Amaimon! Get us the hell outta here! We don't have time!" Rin spoke this in a quiet but fierce tone. Amaimon was impressed he could do this much in his weakened state.  
"Where to?"  
"I don't care! Just out of here!  
"Okay. "  
"Hey Rin! Who ya whispering to up there?" Konekomaru suddenly asked.  
Shit! They were almost here. Rin and Amaimon didn't have much time left.  
"Probably a phone sex call with his girlfriend. What's she wearing Rin?" Shima practically shouted.  
The voices were even closer. Probably just around the corner.  
'Him am I going to get Rin and I out of this?' Amaimon thought. It was then he remembered the key Mephisto had given him. Amaimon bolted to the nearest door, positioned Rin to one hand, grabbed the key and stuck it in the lock of the door. He turned the key and opened the door. He made their destination his human residence and quickly shut the door behind him.  
The three ex-wires heard a door slam open then closed ahead of them. Worried, they ran. They didn't see Rin anywhere.  
\------------------------------------------------  
Amaimon entered his human residence. It was a large apartment given to him by his aniki so he would, and he quotes, "stay out of my office."  
Rin looked around the sparsely furnished apartment and realized he was wearing only a towel.  
"Um... This is rather embarrassing, but do you have anything for me to wear?" Rin asked.  
"Clothing wise, no. I do believe I have a robe though."  
"Then bring me the damn robe!"  
Amaimon walked around the different rooms of the apartment until he found the plain robe he had been looking for. He didn't spend much time in the apartment, so it took a few minutes for him to find it. When Amaimon found it, he gently set Rin down and put the robe on him.  
"You're very lucky I found that robe interesting when I first came here."  
Rin blushed at that comment.  
Amaimon picked Rin up again and started walking to his bedroom. He laid Rin down and crawled in next to him. Rin quickly succumbed into the sleepy feeling he had been fighting until then. Amaimon pulled Rin closer to him and started playing with Rin's hair. He fell asleep with the half-demon practically curled up on him as he played with the little one's hair.

**Notes for the Chapter:**

> Thank you to all who have decided to read this. I have some ideas as to what I want to go on, but I mostly make this stuff up on the spot.  
> To all those who have left comments, thank you for the words of praise. I never expected to see people enjoying this so much!  
> I'll try to update every week or two on the weekends, but I can't promise.  
> And I bid you abdue with a final thank you.


	4. Chapter 4

Rin was having the best sleep he had ever had in his life. The bed was soft, warm, and large. The pillow was comfortable and the small movements it made did nothing to take away that comfort, in fact they enhanced it... Wait, movements?! Rin quickly sat up. He looked down to see that he had been sleeping on Amaimon's chest. "So, you're awake now Rin?" "You tell anyone about this, and I kill you. Got it?" Rin growled at Amaimon almost as if to add to the point. "Okay. Now, why don't you lay back down." "And why the hell should I?" "Because you are still obviously fatigued. That and I believe humans use rest as a form of recuperation." Rin begrudgingly layed back down next to Amaimon, who pulled him closer. After a small complaint, the half demon layed his head back on the others chest. After a few moments Amaimon began to stroke Rin's hair. "Hey Amaimon?" "Yes Rin?" "Where are we?" "In an apartment Mephisto gave me to put my souvenirs of Assiah. I don't usually spend my time here, but I thought it would be appropriate for the situation." "Oh, yeah. Thanks for helping me. I have another question." "And what is it?" "How am I sick?" "I believe it's because your powers are sealed. When you were younger, you may have healed slightly faster than a human, but you still had your abilities sealed in that sword, leaving you open to get a human disease. After you released the Koma Sword from its scabbard, you awakened your demonic powers. Because this sickness had embedded itself into years before the full regenerative abilities of a demon could kick in, you are stuck with said illness. Make sense?" "Yeah, it does. Thanks for explaining that. I haven't been able to understand it since I first found out I was a demon." After that, a comfortable silence came between the two. Amaimon continued to pet Rin's hair and Rin, without realizing it, started to nuzzle into Amaimon's chest. "Rin, you do realize that if you fully excepted your demonic nature you could live right?" "I couldn't give up being human! Or , the closest thing someone like me could get. I saw the reactions of my friends when I got my control back, after the time you tried to kill me on that camping trip. I don't want them to go through that again. " "Okay. I was just letting you know it's a option. " This time, the silence remained. Rin absorbed the information he was just given. He didn't need to be as smart as Yukio to understand what had just been said. Rin fell asleep again while pondering these thoughts.

**Notes for the Chapter:**

> So sorry for updating this late guys! First I had a gianormas book report due, then an essay, plus a propaganda campaign I had to design along with execute, and all my regular school work. I would have updated yesterday, but it was my birthday. I figured sense I got gifts all day, that I'd give one to my readers. Thanks for reading!


	5. Chapter 5

After the second time of waking up, Amaimon took Rin back to his Dorm at True Cross Academy. He really didn’t want to let the half-demon go, but knew it had to be done. Rin had to go back to school, as it was now morning, and Amaimon knew he’d get his ass chewed out by Mephisto if he didn’t have him back soon.  
“Hey, Amaimon, thanks for helping me.”  
“Of course.”  
By now, they’d arrived at Rin’s dorm room. After making sure Rin was okay, Amaimon left through the window. Amaimon had a lot of pent up energy from staying with Rin and not fighting anything, so he decide to try and find a strong enough demon to play with to release his energy.  
Rin got ready for his classes that day. As he finished getting ready, he noticed something on his desk. It was a sucker, obviously left from Amaimon. This making a large smile form on his face. When he had first met Amaimon, he’d thought he was nothing but an insane psychopathic demon hell bent on “playing” with him. But after, spending last night with him and having Amaimon take care of him when his health had taken a turn for the worse made him see the demon in a new light. It was then that Rin remembered Amaimons option, to fully accept the demon part of him or die. He really didn’t want to die, but becoming the monster he was currently learning how to kill wasn’t that appealing of an option either.   
‘Wait, the only thing I know is what I’ve been taught at the cram school,’ he thought to himself. He then had an idea. ‘Hopefully this works.’  
With that he began his day. Other students noticing that he was actually early for once.

After an actually decent day of school, Rin went to the cram school. That too was pleasant until Shima started talking to him.  
“So Rin, who was your lady friend you had over yesterday? Can I have her number?”  
“I never had a lady friend over and even if I did, I still wouldn’t give her number to you.”  
“Come on Okumura! We heard you tal-“  
“Does this mean you’re gay?” Bon interrupted quite loudly, causing everyone who hadn’t been listening to the conversation to turn their heads and pay attention.  
Rin turned bright red at this statement. “W-what?!” he asked.  
“You heard me loud and clear, baka. Are you gay? We heard you talking with someone last night and you went off and hid when we started calling out for you. You wouldn’t have done that if they were just a friend. Only if you didn’t want anyone to know you who you were talking too. Pair that with the fact that you just said the person wasn’t female, so the only logical explanation is that you’re gay. Are you?”  
Rin was absolutely stunned. He didn’t know how to reply to that.  
“I’m… um… actually bisexual, but that’s not why I hid him from you. Hell, you guys would try to kill him the second you saw him!”  
It was then that Konekomaru spoke. “So long as it’s not a demon I don’t think we’d have any reasons to kill your lover Okumura. Unless he’s abusive.”  
Rin stayed quite after that, this tome really not knowing how to reply. After a lot more questions, everybody decided to leave him alone and get back to work.  
Amaimon hadn’t shown up for a few days. Rin was becoming worried. He knew that Amaimon never promised to come back, but he thought that he should have come back by now.  
‘Wait, when did I start getting worried about him? Maybe I like him?’ Rin mused.  
Two days later was when Amaimon finally showed up. He, yet again, went through Rin’s window. He immediately went to Rin, noticing how tired he looked, and held him. With his lips brushing against Amaimon’s neck, Rin spoke. “Hey Amaimon, I have a question for you.”


	6. Chapter 6

**Notes for the Chapter:**

> Holy shit guys, over 1k hits!!! I didn't think my cruddy little story would get so much attention. I don't deserve you guys. Thanks to all who have given this fanfiction a shot, even though I'm an ass and don't update regularly. :)

"Hey Amaimon, I have a question for you."

"Yes?"

Rin at this point leaned back from Amaimon's grasp so he was no longer having his lips brush against the others neck. He wanted to be as serious about this conversation as could be, and talking into the other demons neck was not serious! 

"Could you teach me how to control the demon side of me?"

"What?!"

"If I'm to accept your offer, I want to be able to control the demonic side of me. I don't want to go off on a rampage and I want to control the powers I get from being a demon. Shura can only teach me so much about controlling everything."

"Yay!!! I get to play with Rin!!" Although his face didn't give it away, it almost constantly set at a bored expression, Amaimon's voice let Rin know just how excited he was about this. 

Not only would Amaimon geto spend time with Rin, but they would get to play as well. Amaimon was absolutely ecstatic at the thought. It wasn't every day he got to play with Rin. The last few times, he'd had to steal Kurikara or one of Rin's friends. 

"So... How are we going to do this?" Rin asked. 

"We should probably find a secluded place that won't be easily destroyed. I know how you like the humans."

"And where would that secluded place be?"

"I wouldn't know. Maybe Mephisto has something that could work? He probably has something that could work. Yes, most likely. The problem will be getting him to let use it." At this point Amaimon started talking more to himself then Rin. 

"What the hell are you going on about?!"

"Come with me, Big Brother will probably say yes if you ask him." At this point, Amaimon grabbed Rin's arm and started pulling him towards the door, already pulling the key to Mephisto's office out. 

"What the hell do you think you're doing?!" Rin yelled at Amaimon. 

"Taking you to Big Brother. I already told you that."

Amaimon then put the key in the lock, and twisted. He then opened the door and stepped into the office of Mephisto, dragging Rin in with him. 

"Ooh~, what's this?" Mephisto said with a grin. 

"Rin and I would like to know if you have an areas we could play in. He doesn't want to hurt any humans, and I know how mad you were the last time I got to pick where I played."

"Interesting~. I'm sure I could find something for you two." The grin never leaving the clowns face. 

"Thank you Big Brother."

"Thanks Mephisto."

"Rin?"

"Yes?"

"Make sure you make this entertaining."

Rin didn't know how to respond to that, so he just left with Amaimon through the reopened door. That clown always gave him the creeps!

"Big Brother should let me know soon where we can play. Should we agree on a time to meet?"

"Sure. How about a week from now. That should give Mephisto enough time to find something, right?

"Most likely. I shall see you then Rin."

Amaimon gave Rin a quick kiss on the lips before departing though the window. All Rin could do was stand there in shock. He brought a hand up to his lips, touching them.

**Notes for the Chapter:**

> I know this is a kinda crappy of me. Making you guys wait a little over two weeks and then handing out a short chapter that's mostly dialogue. Sorry! Although it is kind of essential to what I have planned, I know you guys probably want something to actually happen. I promise the next chapter will be much more exciting than this one!


	7. Chapter 7

Rin continued to touch his lips often throughout the week he had to wait for Amaimon. It had become a habit, one that he was thankful no one had noticed yet. The kiss had come as a shock for Rin. He was actually liking spending time with the childish psychopath know as Amaimon, but the kiss was a little quick with their… He didn't know what to call it. Relationship? Still, he enjoyed the kiss. 

After waiting almost a week to question Amaimon, he was finally going to be able to ask him about the kiss and his demon training. Class couldn't pass quickly enough for the impatient half demon. Even thoughts of Yukio coming home in a few days wasn't enough for Rin to keep occupied. Even the anemia getting worse couldn't keep him from thinking about the training with Amaimon. 

Even the rest of the cram school students noticed it, especially Bon and the gang. Rin just looked really happy every time he got lost in thought. 

“Who's the lucky person?” Shima asked Rin, breaking the silence that had gathered in the classroom. 

“What are you talking about?” Was the reply given. 

At this point, Bon decided to add in. “That look on your face. Looks like you're thinking of some dude you like. That, or knowing you, food.”

“I'm not thinking about a guy!” Was nearly shouted by Rin. 

Bon, Shima, and Konekomaru all knew they hit the nail right on the head. “You are thinking about a guy you like.” They spoke in perfect unison. 

Rin blushed heavily. Damn those guys. Couldn't they understand that who he thought about and hung out with were his business, not theirs? He was luckily saved by the teacher dismissing the class. 

He rushed back to the dorms, not wanting to wait any longer for Amaimon. He really wanted to start his training. As he entered the dorm building, he began to feel a little lightheaded and dizzy, but pushed it off as his excitement. Rin ran up the stairs, trying to get to his room as fast as possible. When he reached the floor his room was on, his symptoms got worse. He tried taking a step forward, to get the medicine that would help treat him, but it put him off balance. He tried to grab the banister, but the dizziness was affecting his vision. Failing in his attempts to keep himself steady, Rin fell down the stairs. 

 

"...n!"

“…iN!”

"RIN!”

With that, Rin shot up. He instantly regretted the movement, his head now feeling worse than it had before. Then again, everything hurt right now. He probably even had a few broken bones. Rin peered to his right to see a very worried Amaimon. He must be the one who brought me back to consciousness. Rin thought to himself. 

“Amaimon…what happened to me?” Rin rasped out. 

“I'm not sure Rin. I think you fell down the stairs. Are you okay?” 

“Oh, yeah now I remember… I think I'm okay? I'm pretty sure a few of my bones are broken though. Everything hurts.”

“Well, at least you're alive. Although, from what I know about humans, we're probably going to have to miss today's play time. Oh! By the way, Big Brother and I decided that we would have play times every other day.”

“Sorry that we had to miss today's. I just got dizzy and lightheaded all of a sudden and fell down.”

“Maybe Mephisto has something that could help you with your symptoms for now. Blacking out is a lot more dangerous than a bleeding nose. I can't have you dying on me yet Rin!

“Thanks Amaimon.”

“Well, let's go. I'm sure Big Brother would like to know right away.” And with that, Amaimon picked Rin up bridal style and carried him out the door. 

“We're not using a key?” Rin asked. 

“I want to hold you longer than a few seconds. I haven't seen you in over a week.”

“Okay,” was Rin’s reply. 

A very surprised group of Ex-Wires watched Amaimon leave with a very bloody Rin. It appeared as though they had fought and that Rin had lost. Several bones were obviously broken, but were starting to heal, and there was blood and bruises everywhere. What had happened? As they all processed what they just saw, Amaimon disappeared with an injured Rin. 

 

Mephisto actually did have something to help Rin. Amaimon quickly brought Rin back to his dorm room, this time with a key, after that. He made sure Rin was in a comfortable position on his bed. 

He didn't leave through the window this time. He actually didn't leave at all. 

“You didn't leave this time.”

“Of course not. I'm not going to leave you alone after you black out and fall down the stairs.”

“Thanks Amaimon.”

Amaimon then sat down and cuddle up next to Rin on the small bed. Rin snuggled contently into his demon “pillow”, happy to finally be able to succumb to the call of sleep. Amaimon placed a small kiss on the others forehead. 

“Sleep well Rin.”


	8. Chapter 8

Rin's sleep was peaceful. The comforting presence of Amaimon watching over him, making sure he stayed safe, it just made Rin happy. Usually he dreamed of about the reactions his friends would have about his sickness, but whenever he slept with Amaimon the dreams were kept at bay. 

He snuggled deeper into his pillow. Enjoying the fact that he no longer had to attend regular school and that the cram school started later in the day. That, and after the gate incident the Vatican decided he didn't need constant supervision and gave him his own room in the abandoned dorms along with allowing him to join back in the cram school. 

Amaimon began to pet the navy locks of the younger demon. He couldn't resist, Rin just looked so adorable like this. He somehow pulled the sleeping boy even closer than he was before. 

“We should probably get up, but I don't wanna.”

“Okay Rin, we can stay in bed a little longer.”

They stayed cuddled together until Rin absolutely had to get up. He got dressed and was about ready to head to the cram school. Amaimon walked over to him and pulled Rin into what seemed to be a hug. He brought his nose down to the others neck, inhaling deeply. Then he let Rin go. 

“What was that?”

“You smell nice.”

“Okay… Well I have to leave. Will I see you after the cram school?”

“Yes.”

And with that, Rin left for the cram school. Inserting the key Mephisto had given him –he was surprised he hasn't lost it yet- he twisted it in the lock and entered the school. He walked into the room, surprised at all the shocked stares he received. He sat in his usual seat next to Shiemi, confused by the whole situation. 

“Rin! You're okay!” From Shiemi quickly followed by a “ What the hell happened Okumura?!” Shouted from the others. 

“Yeah, I'm fine. Why wouldn't I be? And the the hell do you guys mean by something happening to me?!” Sure he still was bruised all over thanks to the anemia and still sore, but it was nothing suspicious. What the hell were they going on about?

“We saw you being cared by the Earth King. You looked really beat up. Are you sure you're okay?”

Oh shit! They saw when Amaimon had carried him to Mephisto. How the hell was he supposed to explain that?! Luckily, it was then that the teacher decided to enter the room. 

“What are you doing here Rin. You were switched to that special class by the headmaster. “

“I was?”

“Yeah, now scram.”

Rin left the room. Looked like his training with Amaimon was going to be his class now. It was probably so he wouldn't overwork himself. He wasn't complaining about not being able to go to the cram school anymore though. Yeah, he'd miss his friends, but this way he wouldn't have to hide the anemia anymore. 

He quickly made it back to the dorm room. He went up to Yukio’s room to see his brother passed out on the bed in there. He must have gotten back while Rin was briefly at the school. Must have been a tough mission. 

He quietly walked back to his room. Halfway back his nose began to drip and his mouth filled with blood. Shit! Full on running now, Rin raced back to his room to take the medicine Mephisto gave him. It worked a lot better than the one the doctor had given him. 

He was met with an upside down Amaimon lying on his bed, reading one of the many manga Rin kept around the room. He quickly ran to the drawer holding the medication, his bloody hands staining the wood in the front. Grabbing it, he took a few. He only had to wait a couple minutes before the bleeding stopped. 

“Are you okay Rin?”

This was the second time within ten minutes somebody had asked him that. He was beginning to think that he wasn't. Well, he knew he wasn't doing good anymore, fully excepting it. 

“Yeah, I'm good now.” 

Amaimon got up and walked over to the kneeling Rin. He bent down and gently picked up the other. Carrying him over to the door and pulling the key to the house Mephisto let him use. 

“Where are you taking me?”

“The place Mephisto lets me use. It has a bigger bed. That and you're playing with me now, so you should be nearby.”

“Okay. “

Amaimon proceed through the doorway. He walked into the bedroom and placed Rin on the bed. He curled up next to him, burying his face into the others crook of the neck inhaling deeply. 

“Do I really smell that good?”

“Yes, you do. Each species of demon has a scent. Royalty in Gehena having their own unique one, while the lesser beings share one special to their species. You happen to have a very appealing scent.”

Rin's tail wagged slightly at this. It made him happy knowing the other like how he smelled. He pulled himself closer to Amaimon, allowing the other to smell him more. He quickly fell asleep. 

…

They began training the next day. Amaimon took Rin to the training area Mephisto was allowing them to use. It was located deep under the school. It was rather large and very nondescript. It would do. 

Amaimon first took Rin's sword and pulled the blade out of the scabbard unleashing his flames, much like when they first met except this time it was consensual. As soon as his flames were released, it felt like he had never been sick at all. It was a wonderful feeling having his strength back. 

“First I want you to control your flames. Not like how that exorcist girl showed you how. I want you to be able to control them in this form. Make it so that they aren't constantly surrounding you, only out when you want them to be. Not just because the sword was unsheathed.”

It was a little hard at first, but Rin was soon able to control himself while Kurikara was out. Little did he know that this was just the first step in controlling his flames. 

“Now maintain your control while fighting.”

That was all the warning he had before Amaimon attacked. The control he had built up quickly slipping away, the blue flames covering his entire body. 

“Again.”

This continued on for hours with the same success rate. The most he had been able to hold onto his control after Amaimon began his attacks was two minutes. 

“Enough for now. We'll continue with this until you don't even need to think about controlling your flames when your power is unleashed and you can fight against me without using them.”

“Okay. Thanks Amaimon. You're actually a rather good teacher.”

Rin walked over and grabbed Kurikara. When he sheathed the blade, he instantly regretted it. He immediately collapsed. Blood filling his mouth and streaming from both nostrils. He passed out moments later.


	9. Chapter 9

**Notes for the Chapter:**

> Merry Christmas guys!  
>  I know this ones a little short, but I've been really busy! Hope you like it.

“…!”

“…n!”

“…in!”

“RIN!”

This was the second time I'd been brought back to conscious that way. Did I fall down the stairs again? It was then the memories of before I passed out came back. I'd been training, feeling better than ever, but when I sheathed Kurikara I just collapsed. 

“Amai…mon?” Rin rasped out. 

“Yes!”

Rin tried sitting up, but was immediately pushed back down. He tried to look around, but realized his vision was still spotty. He could barely see anything. 

“How long…was I out?”

“It's been about a day now. How are you feeling?”

With his vision finally returned, Rin looked around. He saw that he was in his room. When he turned his head he saw a rare sight, a worried Amaimon. That and Yukio!!

“Yu…kio?!”

“Nii-san?” 

“What…are you…doing here?”

“Big Brother apparently told him about our training when he went to do an official report of his mission. He was coming back here when I brought you. He made a failed attempt at killing me. After seeing you, we both brought you here. “

“Looks like this asshole went too rough on you Rin. Remember that you're not invincible.” Yukio said. Under his breath he grumbled about Rin having to work with the Earth King for some sort of training, but it was easily heard by the more powerful demons in the room. 

“It's okay…Yukio. Thanks for…worrying about me.”

“It's my job Nii-san. Well, I have lessons that need to be planned. Just because you don't need to learn the material anymore doesn't mean the others don't. And you Earth King, don't you dare hurt Rin!”

And with that, Yukio walked out of the room. With Yukio gone, Amaimon crawled into bed with Rin, pulling him up against his chest and burying his nose into the others neck. Rin pulled slowly pulled the rest of his body over to Amaimon, curling on top of him. 

“So, you still aren't going to tell them?”

“No, I don't want to hurt them. If they knew, they’d either give up on me or suffer right along with me. I don't want either to happen.”

“Okay.”

Rin once again fell asleep next to Amaimon. 

…

Rin was well enough the next day to continue with the training regimen. He was still pretty sluggish, but that would go away after he drew Kurikara. Mephisto had explained that unleashing his power would make all signs of the illness go away, but when sealing his power his demonic half couldn't use enough healing power against his disease and it made an even stronger attack. Leading him so far to black out with minor symptoms, but they would get worse every time he returned back to his human state, the small immunity he had before a being reset after his demonic powers nearly healing him. 

Amaimon had him continue from the day before. After unsheathing Kurikara, he began to work on controlling his flames. Quickly being able to make them last at will. Then the hard part began, fighting Amaimon without unleashing his flames. 

Again and again he tried. At first, like before, his control slipped almost instantaneously. After a while, he was able to beat his old record and reached five minutes. 

“Rin, while you're doing good, work faster! I want to be able to actually play with you.” A whiny Amaimon said. 

“Well I'm sorry this is only my second time doing this.”

And so they continued. Rin was actually improving at a rather quick pace, but it was still no where near what it needed to be. He could now hold onto his control for an average of a little over six minutes. 

It was a race against time. Would Rin be able to master his demonic abilities in time to make his decision on living as a demon? This was the big questions that both were thinking. The symptoms were getting worse everyday and the training they were doing causing his resistance to the anemia to be wiped clean, the odds of him even being alive in time to make the decision was dwindling. 

They both carried on, thinking very similar thoughts on Rin's time left. 

When they finished for the day and sheathed Kurikara, the results were almost the same as the last time. The blood began to pool in his mouth, but also leaked from both nostrils this time. As he was falling to the floor, Rin's foot caught on something. His head slammed into the floor. Blood began to seep from his head wound. 

Amaimon quickly brought Rin to his own home. He attempted to dress Rin's head wound, but wasn't sure on how to properly do it. Amaimon just hoped it would work. He cleaned Rin up, and placed him in the bed. Amaimon himself quickly joining the other. He pulled Rin close and took a quick inhale on the wonderful scent the other produced. Placing a quick kiss on the others forehead, Amaimon fell asleep trying to comfort Rin.

**Notes for the Chapter:**

> I'm starting to write an actual book, so updates might become a little less frequent what with me having to juggle three works. If you guys haven't noticed by now, this fic is going to be coming to a close soon.


	10. Chapter 10

**Notes for the Chapter:**

> So, when reading the comments on my last chapter, Axmr56 left a comment that inspired me to possibly write a oneshot for this series (thanks again for all the praise and encouragement!). They said they were curious about the meeting between Yukio and Amaimon, and I think that's a perfect idea for a oneshot. Let me know if you guys would like me to write it. :)

It'd been three weeks since Amaimon had started training Rin. Everyday was either spent with Rin sleeping or seeing how long his demonic powers could last. After the first week, he could only use them for a few hours. The strain traing was putting on him had progressed the anemia. 

Rin could barely move now; every attempt at moving a few feet would cause him to collapse . Amaimon, who was surprisingly doing an amazing job taking care of the younger half demon, would have to carry him around whenever he needed to go somewhere in the dorm. To help, Mephisto was sending Yukio on longer missions. 

Rin's friends from the exorcist cram school would stop by. When he had been well enough to traverse the dorm, he had talked to them. Shiemi had told him that he was missed and the others were worried about him. Still thinking that Amaimon was out to hurt him. It was better that they thought that. 

Speaking of Amaimon, they had been growing closer together. Amaimon did everything he could to help Rin. He'd make him comfortable, would carry him around, cuddle him, hell he even shared his candy with him. 

When Amaimon found out that Rin was beginning to feel the same way he felt about him he was ecstatic. He would shower Rin with affection and even a couple sweet kisses. He never did anything too heavy though, knowing with Rin's condition it wouldn't go well. But that didn't stop him from showing Rin he cared. 

Whenever he was awake and not spending time with Amaimon, Rin would think. He would think about accepting his demon side and discarding his human body. It was obvious he wasn't going to last much longer in it, but the thought of when Kurikara cracked always kept him from accepting the choice. Although, if he had Amaimon to help him out in Gehena, then he could do it. 

…

Training with Amaimon always was fun. It let him forget for a little while about his ever growing dark thought. Or that he was actually very sick. It was nice in a way. 

Rin had actually improved greatly with his control over his demon self. He could now fight Amaimon without unleashing his flames. Although, the next step was a little harder to do. Amaimon was having him now practice on only using small portions of his power. Meaning only select places and not the whole body could have his flames in a fight and he had to learn to control the temperature. 

“Amaimon! How the hell am I supposed to do this?!”

“I'm not fully sure. I’m not Iblis, I'm Amaimon the Demon King of Earth. Fire is not my speciality. Just try to feel your power and focus it the way you want it to. 

“Believe it or not, learning this control will actually help you as a demon. While most exorcists think of us to be nothing but mindless berserkers. That's only when we succumb to instinct and if you're a powerful demon, your own powers. Now instincts can't be tamed, but you can control your power which in turn helps you control yourself.”

“Don't take this the wrong way, but how the hell do you know so much?”

“Big Brother helped me when I was a little demon. Said it wasn't fitting for a demon king to not have control. He says I don't have a lot, but that it makes me more entertaining.

“That sounds like Mephisto alright.”

They began to spar again, Rin still not quite grasping how to selectively use his flames, but still trying his best. This continued on for another hour and a half before Rin's demonic powers could sustain his ailing body any longer. Passing out with the same bloody results that happened every time. 

…

On the next training day, Amaimon carried out Rin to go to the traing area as usual. He was once agin to preoccupied in his task of carrying the other that he didn't notice the Ex-Wires. 

But they of course noticed him. They saw him once again carrying Rin. They began to follow the Earth King immediately, not wanting to loose him this time. 

Although he was far ahead of them, all of Rin's friends from the cram school were able to keep sight of the demon. They followed him to an abandoned building towards the end of True Cross Town. He disappeared inside, so the others hurried to catch up. 

When they got inside, they saw neither hide nor hair of the Earth King and their friend. They split up and looked all over the building, but try couldn't find the pair. After checking the last room, all began to think along the same lines: what if this was a trap?

They all regrouped in the first room that had come into, the front room. They spread out around the room, trying to figure out where the demon king had taken their friend and what sort of trap could be planned. 

Shima had decided to cross the room and lean against an empty wall. He was shocked when he fell flat on his ass after putting some weight on the wall. 

The others looked over when they heard a shriek from Shima. He had fallen and was very lucky he hadn't gone any further. Because from the passage he had opened, leading down was a winding staircase. 

“What the hell did you do Shima?!” Bon yelled. 

“I just leaned against the wall!”

“Do you think this is where they went?” Izumo was the one who asked this time. 

“There's a very high chance. We didn't see them anywhere in the building and now there's this secret passage. “ Bon answered. 

“I don't think we should go down there. What if there's more demons?” A nervous Konekomaru asked. 

“Might as well give it a shot. Don't want the ladies over there to think that my falling on my ass wasn't to open the passage.”

Everyone gave a small laugh at the pink haired mans remark. Leave it to Shima to try and impress any female in the nearby area. Even when trying to save a friend. 

And with that, they began to go down the staircase.

**Notes for the Chapter:**

> Oh my gosh guys, we're almost finished! Just one chapter left in this one.


	11. Chapter 11

**Notes for the Chapter:**

> Hey guys, last chapter! I wanted to get it out sooner, but like I mentioned in an earlier not segment none of these are pre-typed. I really wanted to start this right after the next one, but I got busy with school and then I hurt two of my fingers. One of them is buddy taped right now (and it still hurts!!) so typing is a little difficult for me. 
> 
> This turned out a little shorter than what I wanted, but I think it works. Even though it ended up being the longest chapter I've written for this series. This one was pretty hard for me to write. 
> 
> Please don't kill me for this chapter...

Everything was going down hill! Nothing was making sense. It was all a misunderstanding, couldn't they see that?

…

Rin and Amaimon went straight to training as soon as the younger demon was set down. He was still struggling to have full control over his demonic side, but he was getting so much better at keeping his head with the rush of instinct and power that side brought out. After training today, he planned on telling Amaimon his choice. He was going to fully accept his demon side.

Amaimon was rather impressed with Rin. While the other always berated himself over not getting control sooner, he was actually completing the necessary steps in traing a young demon rather quick. This bastard child of Satan is rather impressive.

All the more reason to love him more. Amaimon's cared filled feelings had quickly turned to love for the other. While the exorcists thought demons to be heartless monsters, they weren't. They fell in love just like humans did, although their love was slightly different.

Rin's initial feelings had changed as well. At first, he hated Amaimon. Why wouldn't he? The demon had tried to kill him several times. When he was first told his anemia was more than the doctors thought and was now terminal, he had been wary of Amaimon. The demon had actually been kind. Slowly but surely, he began to accept the demons feelings and even had begun to care for him as well. Hell, he fell in love with him!

With these thoughts in mind, the two began to push Rin even harder that day. Both not wanting to loose the other. Even though it had only been a few months since Amaimon was fully informed about Rin's illness, both demons had already fallen for the other and refused to give each other up.

They were so caught up in this, they didn't pay attention to the creaking of the floor above them. Or the opening of the door that led to the large underground training room followed by footsteps going down the stairs.

…

Why? Why, why, why? That's all he wanted to know. There were so many why's that he wanted to ask. To know. Why? Why, why, why?

…

There was nothing that could have prepared the group of Ex-Wires for what they saw when the reached the bottom of the staircase.

Amaimon and Rin were fighting! Rin didn't even have his sword. It appeared to have been knocked out of his hands before they go down there and had landed close to the entrance of the staircase.

They seemed to be going all out against each other. The abilities the Earth King posses we're countering the the blaze of Rin's blue flames. All were too shocked to notice that his whole body was not covered in flames like it normally was when Kurikara is unsheathed, merely the flames would jump around to parts of his body when necessary.

They had to help their friend!

…

You can't ever leave me! Never! I won't allow it! You can't leave me alone!

…

Rin and Amaimon began to really get into it. Amaimon had even started to use his own demonic powers, something that didn't happen often in their training. He also realized that it was much easier to control his flames when he wasn't focusing on controlling them. It was really hard for him to explain the process, but it was almost as if the less he forced his will onto his demonic side the more accepting every part of him was of itself.

They never even realized the Ex-Wires had entered the room. Or that they were about ready to attack.

…

I'll kill them all! Every last one of them for what they did! Why are you trying to leave me?! I will never forgive you if you do! Never. You're breaking me…

...

They were going to attack Amaimon with everything they had. They had to get him away from Rin! It looked like he was going to kill him!

Shiemi summoned Nee, instructing him to use a sharp thorny vine to capture the demon king when the attack began.

Izumo summoned her two white foxes and Shima brought out his k’rik. Konekomaru, while not being able to do much, began to try and find the demon king’s fatal verse. Bon lastly, while not having a weapon of his own, picked up the discarded Koma sword.

The attack began. Shima and Bon charged, aiming to hit the Demon King of Earth. Shiemi and Izumo let their familiars attack. The Ex-Wires all aiming to kill Amaimon.

Rin, finally noticed the presence of the others. Out of the corner of his eye, he saw two of his friends charge and the familiars of the others charging with them. Konekomaru standing back, still trying to figure out the fatal verse of Amaimon.

Rin jumped in front of Amaimon, knowing him to be their target. Kurikara and the k’r stabbed through him along with the thorny vines from Nee all as the foxes began to rip into his flesh. Kurikara and the vines making it all the way through his body, no doubt hitting vital organs. The foxes of Izumo tearing into him. It was all he could do not to scream.

Realizing Rin had jumped in front of Amaimon, the others dropped their weapons. The familiars disappearing now that their masters had no use for them.

Rin collapsed to the ground, blood pouring out of his wounds. It was obvious that even his demonic healing abilities wouldn't even help the situation. He was going to die…

Amaimon shrieked, falling onto his knees next to Rin. “No, you can't leave me Rin! Not yet! Why?!”

He turned to them, a feral look in his eyes. “You did this to him you filthy humans! Over something you misunderstood. I'm going to kill you for this!”

Rin weakly grasped Amaimon's hand, using most of his strength to do so.

“Please…don't kill…them. They…didn't know…we…were…playing. It's…not their…fault. Be…sides…I now…got to…save…you…like you…save…me…all the…time.” There was a sad smile present on Rin's face, as his weak pulse began to slow.

Amaimon screamed in sorrow and rage. He wouldn't allow him to leave!

“I won't forgive you! You've gone and taken what's mine!” He yelled at the exorcists.

He quickly grabbed Kurikara from where the boy with the funny stripped hair had dropped it. With one hand cradling the body of the half demon he loved, he securely held the blade in his free hand.

SNAP

The blade of Kurikara shattered in the hand of the demon.

 

   **Sequel and oneshot are now posted. The oneshot is called Can I Go? and the sequel is titled Chasing Foolish Dreams. Hope you like them!**

**Notes for the Chapter:**

> Again, please don't kill me!!
> 
> I may or may not write a sequel for this. It all depends on you guys.

**Author's Note:**

> This is my first fan fiction, so if it's not that good, blame it on my current lack of experience. I'm a fan on this ship, and there aren't a lot of fanfics about it so I thought I'd add my own. I know Rin acts differently in this, but it has to be this way for my idea to work. I very much enjoyed writing it, and hope you enjoyed reading it. Constructive criticism and tips are very much appreciated. If people like my story, I will be more than happy to continue.


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